The city fell short of 250 megawatt (MW) of power on Monday,leading to intermittent power cuts through the day in parts of the national capital.

Officials said the shortage was because of low supply to Northern Grid  from where Delhi draws a major portion of its power  due to outage in hydro power plants in Himachal Pradesh.

Delhi was short of 250 MW of power from the Agra-Gwalior grid line,officials said.

There is shortage of 3,000 MW of power in the Northern Grid,due to outage of hydro power plants in Himachal Pradesh. These plants were shutdown because of high level of silt. Besides,inter-regional lines are also overloaded, a spokesperson for Delhi Transco Limited (DTL) said.

Officials at Delhis Power department said technically there is no shortage of power in the city,which has a surplus of 1,000 MW in its kitty.

Generation is down at three power stations,but it is likely to get sorted by Tuesday. Technically,all the northern states have been drawing power through the Agra-Gwalior grid,which got overloaded. So while there is no shortage of power so far,technically,load-shedding was an important step or the grid line would have failed again, a senior official said.

DTL officials said load-shedding to the tune of 50 MW to 250 MW was carried out on rotational basis from noon on Monday. Delhi has made sufficient power arrangements,but the shedding was carried out to maintain grid discipline, the spokesperson said.

Parts of West Delhi  particularly Dwarka,Vikaspuri,Janakpuri,Sagarpur,Uttam Nagar,Tilak Nagar and neighbouring areas  reported power cuts lasting more than five hours.

Parts of South,East and North Delhi,too,experienced intermittent power cuts.

The outages added to troubles of the residents as Delhi witnessed high humidity and heatwave conditions on Monday. The maximum temperature recorded was 41.6 degrees Celsius and the humidity level stayed above 50 per cent.

Why the city is sweating?

Private power distribution companies (discoms) in Delhi have no control or jurisdiction over the generation or transmission of power. They only retail,or distribute,the available electricity.

The Power department claims there is no shortage,but the private discoms in Delhi say there are several constraints due to external factors,most of which are beyond (their) control.

Sources in discoms say low frequency in the Northern Grid and other constraints related to the

Grid result in unaccounted power cuts in the city.

Shortage of coal has also been one an important factor leading to lower generation at power at stations,leading to low supply to Delhi,and hence the power cuts.

Other reasons include breakdowns in transmission lines and other equipment,as also capacity constraints and issues with over loading at the transmission level. Many a times,the generator is not able to make available the scheduled power,and there is no option but to cut supply, a source said.

In such cases,officials said,it takes a discom a minimum of 24 hours to arrange additional power.